(PS2-D94) Inhibitory Control Moderates the Relationship Between Compulsive Behavior and Non-suicidal Self-injury

Disasters, stressful life events, or strong negative affect, may trigger individuals to engage in maladaptive coping behaviors such as self-harm. Non-suicidal Self-Injury (NSSI) is associated with many risky behaviors and is one of the strongest predictors of suicide. Identifying which groups may be most at risk is crucial in preventing individuals from engaging in NSSI. The current study presents a novel model aimed at identifying one such at risk group. The model examines the roles of trait compulsivity and inhibitory control together in predicting lifetime NSSI. Using Bayesian modeling, we assessed whether participants’ trait compulsivity (using the Obsessive-Compulsive Inventory - Revised version; OCI-R), moderated by their inhibitory control (assessed using the stop-signal task), could predict lifetime NSSI (measured through the Inventory of Statements about Self-Injury). Results supported the hypothesis that there is a strong relationship between compulsivity and NSSI. In addition, the Bayes Factor for the interaction between compulsivity and inhibitory control to predict NSSI, was 12.8 (BF₁₀=12.8). Simple slopes analyses of the interaction indicated that higher levels of trait compulsivity predict lifetime NSSI only for individuals with average and above-average inhibitory control. In other words, individuals with high trait compulsivity, who also had average, and even above average, inhibitory abilities are at higher risk of having engaged in lifetime NSSI, which makes them a potentially at-risk group which has been understudied. Based on the model, we do not know what the relationship between compulsivity and NSSI is for individuals with low inhibitory control, but we speculate that the uncertain relationship between compulsivity and inhibitory control could indicate that there is a separate, distinguished, mechanism for predicting NSSI for individuals with low inhibitory control. However, this remains to be further studied. Understanding which factors interact to predict NSSI could influence future interventions, especially when targeting a group that is often overlooked, such as those with above average (as opposed to deficient) inhibitory control.